Action de l'ecdystérone sur l'apolysis et l'ecdysis de divers crustacés isopodes

Ecdysterone acts differently according to the period of the moulting cycle when it is applied. In period C it induces apolysis, while at the beginning of apolysis it delays ecdysis. Experiments show that the exoskeleton cannot be rejected in the presence of ecdysterone. The possibility of stopping exuviation or ecdysis with ecdysterone seems to prove that this phenomenon is controlled by a particular factor called the factor of exuviation or the ecdysis factor. Ecdysterone would control only the release of this specific factor but would not prevent its action.     

Purification de l'alcool deshydrogénase de tomate par chromatographie d'affinité

Tomato alcohol dehydrogenase has been purified 99-fold by affinity chromatography on Blue Sepharose CL-6B with 37% yield. The enzyme so obtained is homogenous in polyacrylamide gel electrophoresis. By adding 20% glycerol to the extraction and purification buffers, an enzyme is obtained which is stable for several months at 4°. The molecular weight values determined by gel filtration (Sephadex G 200) and polyacrylamide gradient gel electrophoresis on one hand and by polyacrylamide gel electrophoresis in sodium dodecyl sulfate on the other, show that the enzyme exists in dimeric form.     

Structure cristalline d'une deuxième forme de mélézitose monohydrate. Effet de l'environnement sur la géométrie d'un oligosaccharide

Melezitose [O-α-d-glucopyranosyl-(1→3)-β-d-fructofuranosyl α-d-glucopyranoside] monohydrate crystallizes in two polymorphic forms (I and II). The structure of form II, studied by X-ray crystallography, shows an orthorhombic cell having a 7.135 (4), b 15.362 (8), c 19.134 (8) Å, space group P2₁2₁2₁, and Z 4. The structure, solved by direct methods, was refined to a final value of R 0.045. The molecule of form II seems to be more constrained by its crystalline environment than that of form I. These constraints imply not only little variations in glycosidic bonds, but also a change of conformation for the furanose ring, and a perceptible deformation of the sucrose pyranose ring. This study gives an example of estimation of oligosaccharide molecular-flexibility.     

Modalités d'installation et d'évolutiondes Harpocératinés (ammonitina A) au Domérien inférieur dans le sud-Ouest de l'Europe (France,Portugal)

In Mesogea, the Harpoceratinae were known asearly as the end of the Lower Carixian. They later reached the sub-boreal province through the Alps or the South of the Iberic Peninsula. The analysis of the populations met in four crosssections of the Lower Domerian (Causses, Mâconnais, Franche-Comté, Portugal) showed the settling down of the Protogrammoceras isseli group that set up and evoluated in a similar way in the different areas in spite of a certain originality.On the one hand, it gave the cladogenetic groupP. monestieri-nitescens by diminution of the ribing density, strengthening of the ribs and simplification of the suture.On the other hand, a slower evolution give, near the end of the Stokesi zone, P. normanianum in the Paris Basin and in Burgundy, and P. lusitanicum in Portugal. At the same time, a new invader, P. celebratum, arrived in the Causses (and in Portugal).     

Activité cytokinine de dérivés acylés,alkylés,acyl-alkylés de l'adénine et d'isost`eres azotés de la γ,γ-diméthylallyladénine

The cytokinin activities of various 6-acylaminopurines, 6-alkylaminopurines, 6-acylamino-9-benzyl-purines as well as a series of isosteric-nitrogen derivatives of N⁶-(γ, γ-dimethylallyl)adenine (I⁶Ade) have been tested using the tobacco pith and the pea bud bioassays. The interactions between active, slightly active and inactive compounds have been studied with the last assay. Acylation decreases the biological activity; e.g., N⁶-benzoyl and N⁶-furoyladenines are less active than Na⁶-benzyladenine and kinetin. Substitution at the 9-position reduces (tobacco-pith assay) or suppresses (pea-bud assay) the phytohormonal activity of otherwise active 6-acylaminopurines. In isosteric derivatives, maximum activity occurs when the side chain has the same length as in 1⁶Ade. After the analysis of interactions between more or less active compounds, it is suggested that the differences in cytokinin activity could be related to unequal affinities for a hypothetical receptor site.     

Analyse biostratigraphique et paléontologique de l'Albien marin d'Estremadura (Portugal)

The marine Albain from Estremadura is splited up into four Orbitolinidae zones, adjusted to biostratigraphic scales from mesogean province: zone with Orbitolina (Mesorbitolina) minuta (lower to middle Albian); zone with Neorbitolinopsis conulus (base of upper Albian); zone with Orbitolina (Orbitolina) concava (top of upper Albian) and zone with Orbitolina (Orbitolina) duranddelgai (Vraconian). The vertical extension of the main fossils is replaced in the framework of these zones. The most interesting species for biostratigraphy, paleoecology or taxinomy are summarily described.     

Les vertébrés dévoniens de l'Iran central I: Dipneustes

The dipnoan dental plates discovered in the Frasnian of the Kerman region (Central Iran) are referred to the genera Rhinodipterus, ? Dipterus and ? Chirodipterus. The new taxon Iranorhynchus seyedemamii n. g., n. sp. is erected for a peculiar lower jaw with an elongate, spatula-shaped symphysial region, and with all the ventral and lateral dermal bones fused into a continuous exoskeleton. Furthermore, this lower jaw possesses a well-developed system of symphysial tubuli which is related to the bottle-shaped cavities of the exoskeleton (pore-canal system). A snout fragment from a large dipnoan is provisionnally referred to a rhynchodipterid.     

Relation métabolique entre l'arginine et l'acide γ-aminobutyrique dans le fruit de Castanea sativa: étude préliminaire de l'arginase

Analysis of the free amino acid pool in the chestnut fruit (Castanea sativa) shows that it is high in γ-aminobutyric acid. A metabolic connection between arginine and γ-aminobutyric acid is evident. Three enzymatic activities are involved: L-arginine ureohydrolase, L-ornithine 2-oxo-acid aminotransferase and L-glutamate carboxylyase.     

A propos des fossiles du Pliocène d'Aguilas(Sud d'Almeria,Espagne) découverte de Cirripèdes operculés (Crustacés) et discussion sur l'étho-écologie des formes épizoaires

A benthic taphocoenose from the Pliocene I of Aguilas (provinces of Murcia-Almeria, Southern Spain) conseals four Cirripedia (family of BalanidaeLeach): Balanus (Balanus) perforatus angustusGmelin, B. (B.) amphitriteDarwin, B. (Megabalanus) tintinnabulum tintinnabulumLinné and Creusia (Withersia) phryxaPajaud.The study of the last one is especially interestingfrom an ecological point of view. Indeed, all species, well-known in the Creusia-Pyrgoma group are more or less dependent on Anthozoa since Miocene, the cuplike basis of their shell buried on corallites. But not corallites were gathered in the deposits of Aguilas and the morphology of Creusia phryxa leads us to believe a fixation of the shell on a flaccid substratum. From which we may suppose that the host of this Cirriped was perhaps an Actiniaria.     

Paléohistologie et paléobiochimie des vertébrés dans les Annales de Paléontologie

With the exception of one paper published in 1929, works in vertebrate paleohistology start to be published in the journal in 1968 and are published ever since. Similarly, the first paper in vertebrate paleobiochemistry is published in the journal in 1987 and the field is regularly covered ever since. The relatively late publication of paleohistological researches in the journal is all the more surprizing because there are evidences now that several laboratories at the Paris Museum heavily invested in paleohistology already in the 1870–1890th and gathered extensive collections of thin sections, but very few publications followed. The scientific and contextual causes of the late development of the paleohistological publications in the journal are briefly analyzed. It appears that its history is a fairly faithful reflection of several changing scientific and historical constraints which framed not only french paleontology (and notably the “Paris school”) but french biology as well during the XXth century.     

Nanisme écologique de deux espèces d'échinides irréguliers dans l'Hauterivien de la région de Castellane (Alpes-de-Haute-Provence)

Three species of irregular see-urchins form the settlement of a marly level (lower Hauterivian) of the Castellane area. Two of them are strongly smaller than the norm. Their stunting is prouved by ontogenic, mecanical, sedimentological and ecological arguments. The ecological grounds of stunting are discussed.     

Réflexions critiques sur l'écologieet la systématique des Lingules actuelles et fossiles

New topics on ecology and systematics of recent and fossil Lingulids lead to an obvious revision of our knowledges on this zoological group. At first, the recent species need systematics and taxonomy on the bases of new described specific criteria (as, morphology of deltidial areas, muscle disposition); the results are briefly indicated. But, in fossil species, disorder and disparity of used characteristics are emphasized.The general conceiving on ecology of Lingulids are reviewed and discussed, especially on bathymetry and salinity; sediment and oxygenation conditions; taphocoenosis and lingulid «communities. On recent species, all these points are also studied, especially some ecological requirements (salinity, bathymetry, grain size), and mechanism of burrowing ability, burrow living positions in the sediments, as shell preservations after death and fossilization, to facilitate the paleobiotope interpretations. Recent animals are euryhalin, surviving at salinities from about 13 to 42‰; they could be considered as well adapted to waters with strong salinity fluctuations. They show preference to fine sand bottoms (lowest particle size about 40–60 μm). Their bathymetric distribution occurs between 0 and about 500 m (Lingula especially between 5–50 m; Glottidia 15–70 m). The isotherms 8–10°C seem to restrict their geographical and bathymetric distribution.Therefore, some post-palaeozoic lingulid bedsare studied or redescribed on the bases of the above discussed characteristics, and new interpretations on the environmental situation are given (Trias of Vosges Mountains; Oligocene from Japan; Eocene of London Basin). More caution must be used in study of fossil Lingulids that are not especially animals living in infralittoral bottoms with low salinity and deficient oxygenation, as generally accepted.     

L'encapsulation hémocytaire expérimentale chez le lépisme Thermobia domestica

The introduction of inert foreign objects into the thorax of the thysanuran Thermobia domestica provoked the formation of a cellular capsule, the development and fine structure of which were examined.Encapsulation at first simply results from the accumulation of blood cells around the implant. It is possible to distinguish 48 hr later four regions in the cellular capsule: (1) An exterior layer including normal haemocytes. (2) An intermediate layer formed by homogeneous intercellular electron-dense material and by stretched haemocytes. These haemocytes have numerous microtubules, without any granular particles, and are linked together by desmosomes. (3) An interior layer of cells in the process of necrosis and rich in lysosomes. (4) A very thin limiting layer tentatively interpreted as melanin.The large number of haemocytes devoid of the specific features of the fibroblasts and the very important reduction of the acellular material without collagen fibrils distinguish clearly the cellular capsules of the Insecta from the granuloma of the Vertebrata and other groups.     

Scolécodontes,assemblage et appareil de vers annelidespolychetes errantes de l'aptien de la région d'Agadir,Maroc

From the Aptian scolecodonts inventory of the Agadir area one jaw apparatus and one joining of polychetes are reconstructed. One is the elementary species Schistomeringos expectatusSzaniawski & Gazdzicki, 1978, the oldest representative of the multielementary family Dorvilleidae Chamberlin 1919. The other is a representative of either the multielementary families Atraktoprionidae Kielan Jaworowska 1966 emend. Kozur, 1970 or Arabellidae Hartman 1944. This joining is considered as an hypothesis since all the necessary criteria, defined by H. Szaniawski & A. Gazdzicki 1978, are not all present.     

L'action exercée par l'appareil endocrine sur les phases tardives de l'ovogenèse chez Locusta migratoria

Most studies dealing with the endocrine control of oogenesis are focused on vitellogenesis, but the later events of oogenesis: vitelline membrane formation and choriogenesis have received less atention. In Locusta migratoria, the corpora allata evidently control vitellogenesis, but seem to have no bearing upon the formation of the vitelline membrane or the chorion. If the insects are deprived of their CA at the time when the oocyte length is around 3.5 to 4 mm, (normal length at egg laying: 6.5 mm) vitelline membrane formation and the chorion production are unaffected. In the same species, the electrocoagulation of the pars intercerebralis or excision of corpora cardiaca disturb oogenesis; vitelline membrane material is synthesized and secreted, but the primary granules fail to join each other and to transform into vitelline membrane and the production of chorionic material is disturbed.The rER of the follicle cell seems quite active but the substance elaborated accumulates in the Golgi saccules, and therefore the cytoplasm contains only very few secretory granules. The implantation of supernumerary pars intercerebralis and corpora cardiaca into immature females induces precocious deposition of the vitelline membrane which is complete in 5.0 mm oocytes (instead of 5.6 to 6.0 mm) and chorion formation is completed in 5.5 mm oocytes (instead of 6.0 to 6.3 mm). Ecdysone is secreted in the ovaries at the end of oogenesis. We tested the result of injecting ecdysone to immature females. It results in hastening oocyte growth during 24 hr, but this accelerated growth is followed by degeneration.